摘要
Exploiting biomass polyurethane (PU) coatings derived from vegetable oil adhere to sustainable development strategy, however it faces challenge like inferior wet bonding performance and insufficient protective properties to concrete under harsh marine environment. In this work, inspired by the catecholic chemistry of mussels, the eco-friendly biomass PU was synthesized by hydroxylation and stepwise polymerization of epoxy soybean oil, and by utilizing the catechol-based chemical covalent crosslinking combined with incorporation of polydopamine (PDA) surface modified MXene to composite modify the biomass PU, aiming at enhancing the interfacial bonding performance on moist concrete and its protective properties simultaneously. The Biomass PU composite coating's mechanical and thermal properties, crystallinity, UV aging resistance, water resistance and protective performance of concrete were systematically investigated, the interfacial bonding on wet substrates and protection mechanisms between the Biomass PU and cement-based materials were also revealed. The results demonstrated that DA covalent cross-linking and incorporating PDA@MXene nanosheets into the biomass PU composite significantly enhanced the wet bonding and protective performance to the cementitious substrate. The synergistic enhancement effects of cohesion strength of the biomass PU and favorable interfacial interaction promote the wet bonding strength. The strong covalent crosslink formed between PDA@MXene and the Biomass PU minimized interfacial defects and improved interfacial compatibility, while the well-dispersed PDA@MXene within the PU matrix created a labyrinth effect that extended the diffusion pathways of water and corrosive ion. This work provided a sustainable approach for constructing high-performance biomass PU coatings, offering an effective solution for the long-term corrosion protection of cementitious materials.
危险品化学品经营许可证（带存储）